Model definition

To define mappings between a model and a table, use the define method. Each column must have a datatype, see more about datatypes.

  1. class Project extends Model {}
  2. Project.init({
  3.   title: Sequelize.STRING,
  4.   description: Sequelize.TEXT
  5. }, { sequelize, modelName: 'project' });
  7. class Task extends Model {}
  8. Task.init({
  9.   title: Sequelize.STRING,
  10.   description: Sequelize.TEXT,
  11.   deadline: Sequelize.DATE
  12. }, { sequelize, modelName: 'task' })

Apart from datatypes, there are plenty of options that you can set on each column.

  1. class Foo extends Model {}
  2. Foo.init({
  3.  // instantiating will automatically set the flag to true if not set
  4.  flag: { type: Sequelize.BOOLEAN, allowNull: false, defaultValue: true },
  6.  // default values for dates => current time
  7.  myDate: { type: Sequelize.DATE, defaultValue: Sequelize.NOW },
  9.  // setting allowNull to false will add NOT NULL to the column, which means an error will be
  10.  // thrown from the DB when the query is executed if the column is null. If you want to check that a value
  11.  // is not null before querying the DB, look at the validations section below.
  12.  title: { type: Sequelize.STRING, allowNull: false },
  14.  // Creating two objects with the same value will throw an error. The unique property can be either a
  15.  // boolean, or a string. If you provide the same string for multiple columns, they will form a
  16.  // composite unique key.
  17.  uniqueOne: { type: Sequelize.STRING,  unique: 'compositeIndex' },
  18.  uniqueTwo: { type: Sequelize.INTEGER, unique: 'compositeIndex' },
  20.  // The unique property is simply a shorthand to create a unique constraint.
  21.  someUnique: { type: Sequelize.STRING, unique: true },
  23.  // It's exactly the same as creating the index in the model's options.
  24.  { someUnique: { type: Sequelize.STRING } },
  25.  { indexes: [ { unique: true, fields: [ 'someUnique' ] } ] },
  27.  // Go on reading for further information about primary keys
  28.  identifier: { type: Sequelize.STRING, primaryKey: true },
  30.  // autoIncrement can be used to create auto_incrementing integer columns
  31.  incrementMe: { type: Sequelize.INTEGER, autoIncrement: true },
  33.  // You can specify a custom column name via the 'field' attribute:
  34.  fieldWithUnderscores: { type: Sequelize.STRING, field: 'field_with_underscores' },
  36.  // It is possible to create foreign keys:
  37.  bar_id: {
  38.    type: Sequelize.INTEGER,
  40.    references: {
  41.      // This is a reference to another model
  42.      model: Bar,
  44.      // This is the column name of the referenced model
  45.      key: 'id',
  47.      // This declares when to check the foreign key constraint. PostgreSQL only.
  48.      deferrable: Sequelize.Deferrable.INITIALLY_IMMEDIATE
  49.    }
  50.  },
  52.  // It is possible to add comments on columns for MySQL, PostgreSQL and MSSQL only
  53.  commentMe: {
  54.    type: Sequelize.INTEGER,
  56.    comment: 'This is a column name that has a comment'
  57.  }
  58. }, {
  59.   sequelize,
  60.   modelName: 'foo'
  61. });

The comment option can also be used on a table, see model configuration.